Operational amplifier
AssigneeRohm Co., Ltd.
InventorsHiroyuki Makimoto, Yusuke Yoshii, Yuki Inoue
Life of this patent
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Abstract
An operational amplifier 1 comprises transistors Q1 and Q2 forming an input stage, and input resistors R1 and R2 which form a filter together with parasitic capacitors C1 and C2 accompanying the transistors Q1 and Q2. Resistance values R of the resistors R1 and R2 may be set to R=1/(2π·fc·C), where C is the capacitance value of each of the parasitic capacitors C1 and C2, and fc is the target cutoff frequency of the filter. The operational amplifier 1 may also include a power supply resistor R0 which forms a filter together with a parasitic capacitor C0 accompanying a power supply line.
Claims19
A semiconductor device comprising:
- an operational amplifier;
- a reference current setting portion configured to set a reference current for the operational amplifier;
- a power supply line configured to be connected to a power supply terminal and to the operational amplifier;
- a ground line configured to be connected to a ground terminal and to the operational amplifier;
- and
- a reference current setting line configured to be connected to the reference current setting portion and to the operational amplifier,
- wherein
- the operational amplifier is arranged in a region nearer to one side of the semiconductor device than the reference current setting portion is, and
- the power supply line and the reference current setting line are laid in a region farther from the one side of the semiconductor device than the ground line is.
Dependencies are inferred from the claim text.